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United States Patent |
6,192,918
|
Jaasma
,   et al.
|
February 27, 2001
|
Pressure vessel assembly
Abstract
The pressure vessel (1) forming the fuel tank has an opening (22) with a
flange (3) to accept a flanged accessories plate (4) as a lid. A plate has
a fuel outlet (12), a fuel return (13), a blow-off safety valve (15) and a
filling line. A fuel pump (11) is suspended off the plate with electrical
connections (16) to drive the pump. The pump is suspended from the plate
by exchangeable spacer device (10). It ensures that the bottom of the pump
is near the base of the fuel tank.
Inventors:
|
Jaasma; Servatius Alfons Maria (Eindhoven, NL);
Den Hartog; Marcus Johannes Petrus Gerardus (Eindhoven, NL)
|
Assignee:
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Vialle Beheer B.V. (Eindhoven, NL)
|
Appl. No.:
|
297764 |
Filed:
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June 7, 1999 |
PCT Filed:
|
November 7, 1997
|
PCT NO:
|
PCT/NL97/00610
|
371 Date:
|
June 7, 1999
|
102(e) Date:
|
June 7, 1999
|
PCT PUB.NO.:
|
WO98/20247 |
PCT PUB. Date:
|
May 14, 1998 |
Foreign Application Priority Data
Current U.S. Class: |
137/382; 123/509; 137/565.24; 137/565.34 |
Intern'l Class: |
F02M 037/04; F16K 027/08 |
Field of Search: |
137/382,565.17,565.24,565.34,588
123/509
62/50.6
|
References Cited
U.S. Patent Documents
2673010 | Mar., 1954 | Barrow | 137/382.
|
2932310 | Apr., 1960 | Koblish | 62/50.
|
3014623 | Dec., 1961 | Horn et al.
| |
4593835 | Jun., 1986 | Kikkawa et al. | 62/50.
|
4798522 | Jan., 1989 | Kaga et al. | 137/565.
|
4860545 | Aug., 1989 | Zwick et al. | 62/50.
|
4869225 | Sep., 1989 | Nagata et al. | 123/509.
|
4989572 | Feb., 1991 | Giacomazzi et al. | 123/509.
|
5038741 | Aug., 1991 | Tuckey.
| |
5070849 | Dec., 1991 | Rich et al. | 123/509.
|
5141013 | Aug., 1992 | Zink et al. | 137/382.
|
5613476 | Mar., 1997 | Oi et al. | 123/509.
|
5887617 | Mar., 1999 | Frank | 123/509.
|
5931335 | Aug., 1999 | Cippitani | 137/382.
|
Foreign Patent Documents |
783 739 | Sep., 1972 | BE.
| |
94 11 124 | Dec., 1995 | DE.
| |
0 042 887 | Jan., 1982 | EP.
| |
0 120 343 | Oct., 1984 | EP.
| |
2 462 295 | Feb., 1981 | FR.
| |
Primary Examiner: Rivell; John
Attorney, Agent or Firm: Young & Thompson
Claims
What is claimed is:
1. Pressure vessel assembly for fuel, comprising a pressure vessel with an
opening and a flanged plate to be fitted thereon, which flanged plate is
provided with a number of connections, comprising the fuel outlet from the
vessel, a fuel pump being present in the vessel, characterized in that in
the opening a pipe section is welded, the end of which pipe section facing
the inside of the vessel being provided with a flanged edge, said flanged
plate comprising filling line and blow-off safety valve, and a fuel return
line element.
2. Pressure vessel assembly according to claim 1, wherein said fuel pump is
suspended from the flanged plate solely by way of spacer means of a length
to be selected, said length being selected in such a way that the
underside of the fuel pump is situated near the bottom.
3. Pressure vessel assembly according to claim 2, wherein said spacer means
comprise vibration-damping means.
4. Pressure vessel assembly according to claim 1, provided with a cover,
wherein electronic components are accommodated in said cover.
5. Pressure vessel assembly according to claim 1, in which the pump
comprises a buffer container fitted near the bottom end thereof.
6. Pressure vessel assembly according to claim 5, in which said buffer
container is made of a flexible material and is of such a length when not
deformed that in the fitted position the free end thereof rests against
the bottom of the vessel.
7. Pressure vessel assembly according to claim 5, in which said buffer
container is provided with an inlet valve.
8. Pressure vessel assembly according to claim 5, in which the fuel return
line opens out into said buffer container.
Description
The present invention relates to a pressure vessel assembly according to
the preamble of claim 1.
Such a pressure vessel assembly is known from DE- 94 11 124 U 1. In the
case of conventional pressure vessels such as those for holding LPG a
plate is welded onto a part of the wall thereof, in order to achieve a
greater wall thickness in this way. Holes are tapped in said wall, and the
various inlets, outlets and the like are fitted thereon. Since this is a
relatively complex method, it is proposed in the above prior art to
provide such a so-called accessories plate as a separate part and attach
it to the tank by means of a seal. In this way the accessories plate with
parts mounted thereon can be fitted in the tank in a single operation.
This is important particularly if a complex float device for the filling
level is fitted.
Such an accessories plate is preferably designed for a system with single
line, in the case of which liquefied gas under pressure is supplied to an
internal combustion engine and combusted there. However, a recent
development makes use of an injection system for LPG in which a fuel pump
is used and a return line is present, inter alia, in order to ensure that
liquefied gas is constantly present in the injection lines concerned. In
this case it is essential for such a pump to operate as far as possible in
excess pressure, because when negative pressure is created during the
suction of the liquefied gas there is a danger of this gas passing into
vapour form. For that reason, every effort is made to fit such a pump at
the bottom of a pressure vessel if possible. However, this entails
drawbacks as regards design, because a top opening of considerable size
must be present. Another problem is that tanks with different dimensions
are used, depending on the type of vehicle.
DE-94 11 124 describes a fuel tank for motor vehicles in which the fuel
pump is mounted inside the tank through a spring loaded structure
supporting on the other hand on a vertical mounting rod suspended from the
top wall of the tank.
The object of the present invention is to provide a pressure vessel
assembly in the case of which the fuel pump is easy to fit, and in the
case of which it is always ensured that such a fuel pump is situated near
the bottom of the vessel.
This object is achieved in the case of a pressure vessel assembly of the
type described above by the fact that a fuel pump is present in the
vessel, which fuel pump is suspended from the flanged plate solely by way
of exchangeable spacer means of a length to be selected, said length being
selected in such a way that the underside of the fuel pump is situated
near the bottom, while the accessories plate is provided with a fuel
return line element.
The invention is based on the idea of using the removable accessories plate
known in the prior art. This produces a relatively large opening which can
be used in a particularly effective way for allowing through the fuel
pump. Contrasting with earlier proposals, the fuel pump is not fixed to
the bottom of the vessel, but to the accessories plate, so that it is
possible to mount everything in advance. This is important in particular
for the coupling of pipes, but spacers are used between the accessories
plate and the fuel pump, in order to provide.an adaptation to different
(height) dimensions of the tanks. If these spacers are in the form of
vibration-damping elements such as silent blocks, the advantage obtained
here is that the noise of the pump is insulated as much as possible
relative to the environment.
The accessories plate can be combined in any way known in the prior art
with the box which has to be fitted thereon as a compulsory measure in
many countries. Such a box is an additional safety measure which prevents
gas from escaping to, for example, the boot of the car if there is leakage
between the accessories plate and the various accessories fitted thereon.
For this purpose, a gastight box which is in communication by way of an
outlet with the outside of the vehicle, preferably the underside, is
stipulated. In the event of any leakage, the gas in question will escape
to the outside of the vehicle, so that the risk of explosion during
starting and the like is largely removed. Such an accessories box in the
prior art is a separate expensive casting which has to be fitted by
complicated steps.
According to one-object of the invention, use of such a complex accessories
box is avoided by the fact that the pressure vessel comprises a circular
opening which is made in the pressure vessel and in which a pipe section
is welded, the end of which pipe section facing the inside of the vessel
being provided with the flanged edge, and in which the end facing away
from the inside of the vessel can be provided with a cover, i.e. the
construction for the accessories plate is effectively combined with the
box described above.
The now very simply designed cover can be used in particular for the
accommodation of electronic components. This cover is a relatively cool
part and provides such components with sufficient protection. Such
electronic components comprise in particular circuits relating to the
control of the pump,
Although the pump can comprise any construction known in the prior art, it
is preferably provided with a buffer element fitted in its vicinity. LPG
can be stored in said buffer element, and in particular if the tank is
almost empty, the presence of the buffer element ensures that the pump
does not suck up vapour instead of liquefied gas. A non-return valve is
preferably fitted in the buffer element, so that material din only enter
the buffer element. The buffer element can be made of a relatively
flexible material which can adapt to the local conditions.
According to a further advantageous embodiment, the fuel return line opens
put into the buffer element, so that when the pressure vessel is just
about empty it is ensured that liquid is sucked up as long as possible.
The good heat conduction will mean that the slightly warmer liquid from
the return line is cooled immediately, before being pumped back by the
fuel pump described above.
The invention will be explained in grater detail below with reference to an
exemplary embodiment shown in the drawing, in which:
FIG. 1 shown a side view in cross-section of an embodiment of the pressure
vessel assembly according to the in invention; and
FIG. 2 shows a top view of the part near the pipe 2 according to FIG. 1
with the various accessories.
A pressure vessel is indicated by 1 in the figures. Said pressure vessel is
provided with an opening (not shown in any further detail) in which a pipe
2 is fitted in a gastight manner by welding. Said pipe 2 is provided with
a flanged edge 3 on the side facing the inside of the tack. On the other
side, said pipe is dimensioned in such a way that a cover 5 can be placed
over it and can be tightened by means of a bolt 6. An O-ring 23 is present
between cover 5 and pipe 2. Flanged edge 3 is designed for receiving a
flanged plate 4 thereon. An O-ring 20 provides for the seal, while fixing
is achieved by means of bolts 9. Flanged plate 4 is in the form of an
accessories plate, on which the usual accessories of an LPG tank for a
motor vehicle are situated. These are an inlet 12 provided with a shut-off
valve 14, a return line 13, a release valve 15 and wiring 16 and filling
line 21. Wiring 16 is used for the control of the fuel pump indicated by
11. Fuel pump 11 is fixed on accessories plate 4 by means of
vibration-damping elements such as silent blocks 10. Three of such silent
blocks are present in the case of the embodiment shown here. The height of
the silent blocks, i.e. the distance from the fuel pump 11 to the
accessories plate 4, is selected in such a way that the underside of the
fuel pump is situated close to the bottom of the pressure vessel 1. This
is important because negative pressure, which could lead to vaporization
of the LPG present in the fuel pump, has to be prevented from occurring
therein. Provision can be made for adaptations for tanks with different
heights by using silent blocks of greater or smaller height. In this way
it is always guaranteed that the underside of the pump is situated as
close as possible to the bottom of the pressure vessel. Of course, a
construction can be fitted in the pressure vessel to prevent the pressure
vessel from being filled to more than the legal percentage. Fuel pump 11
is not shown in any further detail, but contains filters and the like in
the usual way. On the underside the fuel pump 11 is provided with bellows
17 which surround it and act as a buffer. Said bellows are made of a
slightly flexible material, of which a number of "feet" 18 rest on the
bottom of the tank. Slight tolerances can be accommodated because of the
flexible nature of the material. This means that the buffer will always
touch the bottom with the flexible sound-damping material, while the pump
is always suspended from the accessories plate by way of the silent blocks
described above. Maximum sound insulation is consequently obtained and, on
the other hand, optimum emptying of the vessel is ensured. Buffer 17 is
provided on the underside with an inlet valve 19 which functions as a
one-way valve. This ensures that when the tank is almost empty and bends
are being negotiated, LPG situated in the buffer can flow back into an
empty part of the pressure vessel.
The construction shown here makes it possible in a simple manner to fix
together the assembly consisting of accessories plate and pump and fit the
tank in one operation. This contrasts with the prior art, in which it was
necessary to fix the pump on the bottom of the pressure vessel by an
extremely complicated operation.
Although the invention is described with reference to a preferred
embodiment, it must be understood that numerous modifications can be made
to it without going beyond the scope of the appended claims.
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